U.S. patent number 8,915,113 [Application Number 12/680,750] was granted by the patent office on 2014-12-23 for deep-drawing device.
This patent grant is currently assigned to Inventio AG. The grantee listed for this patent is Peter Khu, Michael Matheisl, Thomas Novacek. Invention is credited to Peter Khu, Michael Matheisl, Thomas Novacek.
United States Patent |
8,915,113 |
Matheisl , et al. |
December 23, 2014 |
Deep-drawing device
Abstract
The invention relates to a deep-drawing method and a
corresponding deep-drawing device. The deep-drawing device has at
least two projections (112) and at least two corresponding lamellar
gaps (102) in a die (106), the width and positioning (Pi) of the
lamellar gaps (102) being adjustable. Folding of a metal sheet (10)
is brought about by closing the lamellar gaps (102). During the
subsequent deep-drawing process, the projections (112) are lowered
into corresponding recesses (103). Flat metal sheets (10) as well
as previously corrugated metal sheets (10) can be folded and deep
drawn by means of the deep-drawing device and the deep-drawing
method.
Inventors: |
Matheisl; Michael (Vosendorf,
AT), Novacek; Thomas (Schwechat, AT), Khu;
Peter (Vienna, AT) |
Applicant: |
Name |
City |
State |
Country |
Type |
Matheisl; Michael
Novacek; Thomas
Khu; Peter |
Vosendorf
Schwechat
Vienna |
N/A
N/A
N/A |
AT
AT
AT |
|
|
Assignee: |
Inventio AG (Hergiswil NW,
CH)
|
Family
ID: |
40549644 |
Appl.
No.: |
12/680,750 |
Filed: |
September 15, 2008 |
PCT
Filed: |
September 15, 2008 |
PCT No.: |
PCT/EP2008/062249 |
371(c)(1),(2),(4) Date: |
March 30, 2010 |
PCT
Pub. No.: |
WO2009/047088 |
PCT
Pub. Date: |
April 16, 2009 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20100218442 A1 |
Sep 2, 2010 |
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Foreign Application Priority Data
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Oct 1, 2007 [EP] |
|
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07117647 |
Oct 1, 2007 [EP] |
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07117648 |
Oct 1, 2007 [EP] |
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07117651 |
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Current U.S.
Class: |
72/385;
72/379.6 |
Current CPC
Class: |
B21D
22/26 (20130101); B21D 13/02 (20130101) |
Current International
Class: |
B21D
13/02 (20060101); B21D 13/00 (20060101) |
Field of
Search: |
;72/347,385,397,379.6,414 ;52/182 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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358 773 |
|
Dec 1961 |
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CH |
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0 960 664 |
|
Dec 1999 |
|
EP |
|
62 270224 |
|
Nov 1987 |
|
JP |
|
Primary Examiner: Self; Shelley
Assistant Examiner: Yusuf; Mohammad I
Attorney, Agent or Firm: Ladas & Parry LLP
Claims
The invention claimed is:
1. A deep-drawing device for flatly shaped workpieces, comprising:
a tool, a deep-drawing plate having at least two fixed projections,
the tool having corresponding recesses between lamellae, guides for
moving the tool and the deep-drawing plate relative to one another
along a travel axis by a first drive such that the projections of
the deep-drawing plate move into the corresponding recesses of the
tool, the recesses being width-adjustable along a fold axis
perpendicular to the travel axis by a second drive in a range
between a receiving position width for a workpiece and an end
position width, and means for operating the first and second drives
whereby the second drive is first activated whereby the workpiece
is folded into folds in the recesses as the second drive adjusts
the widths of the recesses along the fold axis from the receiving
position width to the end position width, and whereby the first
drive is subsequently activated to move the projections of the
deep-drawing plate into the corresponding recesses of the tool and
the folds of the workpiece, deep-drawing the workpiece folds into a
final shape of the workpiece.
2. A deep-drawing device according to claim 1, wherein the means
for operating the drives provides for adjusting the recesses in
their width and in their positions on the tool.
3. A deep-drawing device according to claim 1 or 2, further
comprising a compressed air device for directing the workpiece
against the tool.
4. A deep-drawing device according to claim 3, further comprising a
flattening plate movable into a position between the workpiece and
deep-drawing plate for folding of the workpiece and pressure means
for supporting the flattening plate against the workpiece at
lamellae of the deep-drawing plate.
5. A deep-drawing device according to claim 1 or 2, wherein the
projections of the deep-drawing plate are at an underside of the
deep-drawing plate and are retractable to a position in which end
surfaces of the projections are co-planar with the underside of the
deep-drawing plate.
6. A deep-drawing device according to claim 1 or 2, wherein the
tool has hydraulically adjustable recesses.
7. A deep-drawing device according to claim 1 or 2, wherein the
tool has recesses which are simultaneously adjustable by means of a
spindle drive.
8. A deep-drawing device according to claim 1 or 2, wherein the
projections have cross-sectional profiles that taper or widen in a
direction towards the deep-drawing plate.
9. A deep-drawing device according to claim 8, wherein the angle of
taper of the projections is chosen to produce a workpiece web angle
between 0 degrees and 17 degrees.
10. A method for deep-drawing a workpiece by a deep-drawing device
comprising a tool with lamellae having intermediate adjustable
recesses, and a deep-drawing plate with at least two projections,
the deep-drawing plate and tool being movable relative to each
other by guides and being driven respectively by first and second
drives, the method comprising the following steps in the following
sequence: introducing the workpiece between the tool and the
deep-drawing plate; adjusting the recesses of the tool from a
receiving position to an end position along a fold axis
perpendicular to a deep-drawing axis by means of a second drive to
fold the workpiece; and subsequently deep-drawing the folded
workpiece by activating the first drive to move the projections of
the deep-drawing plate into the recesses of the tool to shape
depressions in the workpiece and finalize a shape of the
workpiece.
11. A method according to claim 10 for shaping a tread element or
riser element of a step of an escalator, comprising the step of
retaining the workpiece against the tool by means of a compressed
air device after introduction of the workpiece and before
preforming the workpiece.
12. A method according to claim 10 for shaping a tread element or
riser element of a step of an escalator, comprising the following
steps in the following sequence: a. after introduction of the
workpiece: introducing a flattening plate between the workpiece and
the deep-drawing plate and adjusting a spacing between the tool and
the deep-drawing plate so that the flattening plate bears against
the projections of the deep-drawing plate and the workpiece bears
against the thus-supported flattening plate; and b. after
preforming the workpiece adjusting a spacing between the tool and
the deep-drawing plate; and removing the flattening plate.
13. A method for deep-drawing a workpiece by a deep-drawing device
comprising a tool with lamellae having intermediate adjustable
recesses, and a deep-drawing plate with at least two projections
movable relative to the tool by guides and driven by a first drive,
the method comprising the following steps in the following
sequence: setting the recesses of the tool into a receiving
position; introducing the planar metal sheet workpiece between the
tool and the deep-drawing plate; adjusting a first arrangement of
the projections so that the planar metal sheet is to be first
shaped to be wavy; drawing the workpiece by relative movement of
the tool towards the deep-drawing plate by means of the first drive
to form the wavy shape upon the workpiece; retracting the second
arrangement of the projections; adjusting a spacing between the
tool and the deep-drawing plate so that the metal sheet bears
against an underside of the deep-drawing plate; adjusting, by means
of a second drive, the recesses of the tool along a fold axis
perpendicular to a deep-drawing axis from the receiving position to
an end position so that the metal sheet is folded; adjusting a
second arrangement of the projections so that the folded metal
sheet can be deep-drawn by penetration of the projections into the
end position of the recesses of the tool; and deep-drawing the
folded workpiece by relative movement of the tool towards the
deep-drawing plate by means of the first drive so that the
projections of the deep-drawing plate penetrate the recesses of the
tool to shape depressions in the workpiece to finalize the shape of
the workpiece.
14. A tread or riser element produced according to the process of
claim 10, 11, 12 or 13, wherein the workpiece is chosen from the
group consisting of H380, H400, DX 52, DX 56, DX 60, H900 and H1100
steel (fine) deep-draw metal sheets.
Description
The present invention relates to a deep-drawing device and to a
method with a corresponding deep-drawing device.
BACKGROUND OF THE INVENTION
By deep-drawing there is generally understood a compression-tension
reshaping or compression reshaping of flatly shaped workpieces to
form a hollow body open at one side or also only the shaping of
bulges in the surface of the flatly shaped workpiece, in that a die
presses the workpiece into a corresponding die plate.
Deep-drawing in the last-mentioned form finds use in, for example,
the production of steps or tread elements and riser elements of
escalators or of plates of moving walkways. A tread element forms
the tread surface or stand surface for a user of the escalator or
of the moving walkway and a riser element forms the visible front
face of the step in the inclined part of the escalator. Through the
deep-drawing there is achieved, with the stated elements, the
shaping of a web/groove profile which notwithstanding its low
weight is stiffer and narrower than can be achieved by a stamping
method or a pressure moulding method or a rolling method. Moreover,
the web profile or groove profile is provided with a plurality--of
about 88 to approximately 112--of webs and grooves in an escalator
step or moving walkway plate so as to guarantee better standing of
the user and to allow liquids, particularly water, to drain
away.
The preferred narrow web/groove profile is achieved in that a
deep-drawing plate with projections, for example in the form of
teeth, tines or prongs, is guided and moved relative to and/or
comparatively and/or co-operatively and/or compatibly with respect
to a tool with recesses, for example in the form of grooves.
Comparatively means that not only the tool can be pressed against a
stationary deep-drawing plate, but also that a movable deep-drawing
plate can be pressed against a stationary tool. In addition, the
tool can have the projections and the deep-drawing plate the
recesses and thus be equipped in opposite manner. It is merely
fundamental that projections are pressed into corresponding,
complementary recesses.
However, a general disadvantage of deep-drawing is that the
necessary `material deformation flow limit` can contradict
economic, industrial mass production. In the case of simultaneous
deep-drawing of several grooves, which are preferably in a row
closely adjacent to one another, the tear strength or yield point
or breaking strength limit of the material is quickly exceeded.
Consequently, for example, a pressure device is disclosed in the
specification JP-A-62270224 in which the steel sheet is pressed
onto an individual web tool or stamping tool and each web thus
individually formed in succession.
Proceeding from the state of the art and the general problem of
`material deformation flow limit` in deep-drawing the object is set
of finding a deep-drawing device or method steps which enables or
enable simultaneous production of several, preferably all, desired
webs and is thus more economic and faster than previously usual and
customary.
BRIEF DESCRIPTION OF THE INVENTION
The fulfillment of the object in accordance with the invention
resides in the combination of deep-drawing with a prior
adjustability and displaceability of the lamellar gaps of the tool
from a receiving position to an end position for shaping the web
profile or groove profile. The receiving position is so designed
that a metal sheet or deep-draw metal sheet, which is shaped to be
wavy or is profiled, is received by its wave valleys or profile
valleys in the opened lamellar gaps corresponding with the
receiving position. The subsequent adjustment of the tool from the
receiving position to the end position means closing of the
lamellar gaps, which produces a folding of the metal sheet or
deep-draw metal sheet. The tool according to the invention thus
stands in the end position, which provides, for the actual
deep-drawing process, recesses corresponding with the projections.
The simultaneous deep-drawing of each individual groove or each
individual web is thereby possible. The metal sheet or deep-draw
metal sheet, which lies with its eventual tread side downwardly in
the deep-drawing device, thus has more material available. A
multiple and tightly spaced deep-drawing taking place
simultaneously is thereby newly possible.
This new method is faster and more economic than hitherto and
offers increased reserves up to the tear strength limit.
Moreover, the accuracy of the end product or workpiece is
increased, since the tolerances of each individual web, as
disclosed in the specification JP-A-62270224, do not add together
or summate. In the case of the new deep-drawing method according to
the invention there are no summation tolerances from the individual
production of the webs of the tread element or riser element,
whereby there is also no need for costly re-finishing work or
straightening work or calibrating work or rectification work.
A preferred embodiment of a deep-drawing device according to the
invention substantially comprises a base plate, a deep-drawing
plate, a counter-plate with respect to the latter and a tool. The
three plates are equipped with a common guide. The deep-drawing
plate and the counter-plate enclose the tool together with a
workpiece lying thereon. A second drive then presses the
deep-drawing plate against the counter-plate or conversely in a
direction corresponding with a second axis, which corresponds with
the common guide of the plates. The deep-drawing device according
to the invention beyond that comprises a further, first guide and a
further, first drive. This first drive is, by means of the first
guide, in a position of pressing the tool together in a direction
corresponding with a first axis perpendicular to the second axis.
The last-mentioned pressing together has the consequence of closing
of recesses arranged at the tool. As a result, folding of the
workpiece lying on the tool is in turn possible.
The drives can be, for example, hydraulic or electrical or via an
eccentric and the tool can consist of, for example, displaceably
arranged lamellae. These lamellae can in turn run in a separate
guide and preferably have two different thicknesses in their
respective cross-sectional profile. The smaller of the two is in
that case oriented towards the deep-drawing plate. This preferred
form of the lamellae has the effect that the lamellae can be
pressed with maximum pressure against one another towards their
greatest thickness and the smaller thickness thus automatically
forms the recess. This embodiment has the consequence that due to a
higher bending strength of the lamellae a higher dimensional
accuracy of the recesses is achieved during loading by the
deep-drawing.
The shape or form of the slender lamella also prevents jumping out
or self-release of the workpiece from the processing surface or
from the slender lamella.
The displacement movement of the lamellae is, moreover, preferably
coupled with compression springs between the individual lamellae.
This means that preferably at first the mutual impinging of the
first and second lamellae triggers the movement of the second
lamella, thereupon the third lamella, the fourth lamella and so
forth. The initiating movement of the first lamella transfers
itself to the next lamella. The thereby-achieved concertina effect
or accordion effect or lattice grate effect facilitates folding of
the workpiece or the metal sheet with lower force or driving power.
A displaced and successive closing of the recesses is thereby
achieved. The opening and removal of the workpiece is possible, and
able to be accomplished, without problems and with easy motion as
well as smoothly and easily.
This is improved if the compression springs are not arranged
between adjacent lamellae, but a compression spring, for example,
jumps over the adjacent lamella and presses only on the next one or
one beyond that. In addition, the compression springs might not be
arranged between two adjacent lamellae for reasons of space.
Moreover, the design, in accordance with the invention, of a
deep-drawing device with a tool with adjustable recesses provides
that the recesses cannot open out beyond a predetermined open
receiving position for the workpiece. Arranged for this purpose is,
for example, a wire or a flexible cable which connects the
individual lamellae. This wire or this cable on the one hand allows
complete closing of the lamellae to the extent of bearing against
one another and on the other hand does not allow opening of the
lamellae beyond the length of the wire/cable lengths connecting
them. An expert is at liberty to integrate other forms of travel
limitation, for example in the form of latches, hooks or gate
guides, which achieve substantially the same effect.
The simultaneity and homogeneity of the closing and opening of the
recesses described in the foregoing can be achieved, in accordance
with a further preferred embodiment of a deep-drawing device
according to the invention, in that the adjustment is carried out
by means of a special spindle drive with serially arranged threaded
part members. The lamellae are in this regard arranged individually
and guided on the thread of a threaded part member of the spindle,
so that one or also several turns of the spindle have the effect
that each threaded part member moves the lamella associated
therewith from the open receiving position to the closed
deep-drawing position of bearing against one another.
The deep-drawing device according to the invention or the
deep-drawing method according to the invention can in every case be
so adapted with respect to the dimensions of the projections in
relation to the dimensions of the recesses that in conjunction with
the materials indicated by way of example the requirements of the
standards can be fulfilled. This adaptability can be given by the
fact that, for example, the deep-drawing plate and the individual
lamellae are exchangeable.
Very short operating cycles for the production of tread elements or
riser elements can be realised with the deep-drawing device
according to the invention, the appropriate pressing pressures and
the appropriate material. These shorter operating cycles give, by
comparison to operating cycles proposed in the state of the art,
the possibility--beyond the advantageous shortness of the operating
cycle--of the total number of the desired grooves being able to be
produced by a single deep-drawing process.
The deep-drawing device according to the invention functions, for
example, with metal sheets pre-shaped to be wavy.
A further advantage in accordance with the invention is the
simplified withdrawal of the workpiece. The workpiece or the tread
element or riser element can be manually removed from the
deep-drawing device; easier and simpler and quicker is manipulation
by means of ejectors or pressurised air blowers, which lift up the
workpiece and convey it out of the recess and/or out of the
lamellae. The workpiece or the tread element or riser element is
thereafter gripped by a gripper or a robot arm or a metal-sheet
manipulator and withdrawn from the deep-drawing device. The
workpieces or the tread elements or riser elements are subsequently
deposited and/or smoothed and/or smoothed out and/or stacked and/or
collected and/or heaped up and/or palleted.
In a further embodiment of a deep-drawing device according to the
invention a planar surface, along which the corrugation elevations
can slide during folding, is formed in that the deep-drawing
projections are lowerable into the deep-drawing plate. This
lowering preferably takes place so that the lower end face of the
projections forms, together with the underside of the deep-drawing
plate, a planar surface.
The invention is usable for parts of escalators and for parts of
moving walkways. In addition, parts for steps and parts for plates
can equally well be produced.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained in more detail symbolically and by way
of example on the basis of the figures.
The figures are described conjunctively and generally. The same
reference numerals mean the same components; reference numerals
with different indices indicate functionally equivalent or similar
components.
In that case:
FIG. 1 shows a schematic illustration of a deep-drawing device
according to the invention in the open receiving position;
FIG. 2 shows a schematic illustration of the deep-drawing device
according to the invention of FIG. 1 in the closed end
position;
FIG. 3 shows a schematic illustration of the deep-drawing device
according to the invention of FIGS. 1 and 2 in a setting
corresponding with the deep-drawing process;
FIG. 4 shows a schematic illustration of lamellae, which form a
tool and are disposed in the open receiving position;
FIG. 5 shows a schematic illustration of the lamellae of FIG. 4 in
closed end position; and
FIG. 6 shows a schematic illustration of the individual method
steps.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows schematically a deep-drawing device 100 according to
the invention. A deep-drawing plate 110 with an underside 113, at
which projections 112 are arranged, a counter-plate 130 and a base
plate 140 are guided in common in guides 122a to 122d. A drive,
which is not illustrated in more detail, acts by a drive force F2
along these guides 122a to 122d or along a deep-drawing axis A2 so
that the deep-drawing plate 110 and the counter-plate 130 can be
pressed relative to one another. A tool 106 comprises lamellae
which in an open receiving position PA, shown here, of the tool 106
form lamellar gaps 102 or recesses 103. These lamellar gaps 102 are
adjustable, because a ram 120 driven by a further, second drive
(also not illustrated in more detail) so acts by a driving force F1
along a fold axis A1 perpendicular to the deep-drawing axis A2 that
the lamellae 101 are movable along a lateral guide 121.
FIG. 2 shows schematically the deep-drawing device 100 according to
the invention in a closed end position PE. The lamellae 101 bear
against one another. This movement corresponds with a folding
process of a metal sheet which was pre-shaped to be wavy and which
was previously laid in place between the tool 106 and the
deep-drawing plate 110.
FIG. 3 shows schematically the deep-drawing device 100 according to
the invention of FIGS. 1 and 2, wherein the counter-plate 130 is
pressed against the deep-drawing plate 110. This movement
corresponds with a deep-drawing process of the metal sheet folded
in accordance with FIG. 2.
A part of the tool 106 in the open receiving position PA is
illustrated schematically in FIG. 4. It can be seen that the
lamellae 101 form two different thicknesses and a dog 127 is
arranged at the transition from the smaller to the larger
thickness. Springs 104 are so arranged that they are mounted in a
mount at a lamella 101 and, passing through the adjacent lamella,
at the following lamella. In addition, travel limitations in the
form of wire or cable elements 105 are illustrated, which in the
depicted open receiving position PA of the tool 106 stand under
tensile stress and prevent further opening of the lamellar gaps
102.
The illustrated open receiving position PA further clarifies that
the lamellar gaps 102 or the recesses 103 form a width 107, the
centre of which is disposed in a defined position P1 with respect
to an abutment 129 of the tool 106. Similarly schematically
illustrated is the deep-drawing plate 110 with the projections or
teeth 112, wherein it is apparent that the teeth 112 do not
correspond or correspond purely accidentally with the recesses 103.
A workpiece 10 in the form of a metal sheet pre-shaped to be wavy
lies by its wave valleys in the recesses 103 so that subsequent
closing of the lamellar gaps 102 in accordance with the driving
force F1 folds the metal sheet 10. Moreover, an optional compressed
air device 108 is indicated, which presses the metal sheet 10 into
the recesses 103.
FIG. 5 shows the part of the tool 106 of FIG. 4 in the closed end
position PE. FIG. 5 is illustrated on the same sheet as FIG. 4 so
that it can be seen that not only the original width 107 of the
recess 103 has reduced to a width 107', but also the position P1
with respect to the abutment 129 has displaced to a position P2. In
addition, it can be seen that the lamellae 101 bear at the greater
thickness thereof against one another and thus the recesses 103 are
only still defined by the smaller formed thickness of the lamellae
101. The position of the recesses 103 now corresponds, by contrast
with FIG. 4, with the teeth 112 for the deep-drawing. Moreover, it
is illustrated that the springs 104 are compressed and the wire or
cable elements 105 no longer stand under tensile stress.
FIG. 6 shows, by way of example, method steps 2 to 8 according to
the invention or the working steps 2 to 8 of an exemplifying
operating cycle according to the invention, starting from a metal
sheet 10, which has been pre-shaped to be wavy, according to
numeral 1 and going to a deep-drawn metal sheet 10'' according to
numeral 9. At numeral 1, the metal sheet 10 pre-shaped to be wavy
and with a metal sheet thickness S is shown as starting
product.
Numeral 2 shows, as first working step, the introduction of the
metal sheet 10 into the deep-drawing device 100 and, in particular,
so that the wave valleys come to lie on the opened recesses 103. At
the same time, as an optional enhancement for the folding process
following later a flattening plate 109 is introduced between the
metal sheet 10 and the teeth 112 of the deep-drawing plate 110.
Numeral 3 shows, as the next working step, a reduction of a spacing
D to a dimension at which the wave elevations contact the
flattening plate 109 and the flattening plate 109 in turn contacts
the teeth 112 of the deep-drawing plate 110.
The folding process of the metal sheet 10' under the action of the
driving force F1 is illustrated at the numeral 4. Numeral 5 shows
the subsequent opening of the deep-drawing device 100, whereupon,
at numeral 6, the straightening plate 109 is removed.
The position of the significant elements of the deep-drawing device
on attainment of the maximum stroke of the teeth 112 in the
deep-drawing process is illustrated at numeral 7.
Numeral 8 shows the removal from the mould and numeral 9 a
deep-drawn metal sheet 10'', as end product, with a reduced metal
sheet thickness S', a web height 123, a web width 124 of a web 111
and a groove 114 with a groove width 125. The web 111 has beads 128
at its upper side in the depicted sectional illustration. In
addition, the webs 111 have an angle `W` which has an inclination
between 0 degrees and 17 degrees, preferably 2 degrees to 11
degrees. The beads 128 along the upper side of the webs 111 are
kept at small spacings and thereby considerably improve slip
resistance for users of the tread elements and riser elements.
Simultaneous production of the webs 111 inclusive of the edging
with the beads 128 in one working step improves the production
advantage and saves valuable production times and brings additional
productivity. Beyond this, productive work is increased, since all
webs 111 are produced and fabricated simultaneously and at the same
time. The production time and fabrication time of the tread
elements and riser elements are thereby hastened and accelerated.
An improvement of the production process is obvious and is
incessantly, continuously and constantly provided.
The deep-drawing device 100 according to the invention functions,
for example, with a metal sheet 10 pre-shaped to be wavy. This can
be, for example, an approximately 3200 mm wide sheet metal panel,
which has been so (pre-) corrugated that it retains only a width of
approximately 2000 mm. The thus-shaped wave valleys are received
and folded by the edges of the recesses 103 at the tool 106.
A further form of embodiment of a deep-drawing device 100 according
to the invention proposes that use can also be made of a smooth,
metal sheet 10 which has not been pre-shaped. For this purpose a
smooth sheet 10 is placed on the tool 106, the recesses 103 of
which are in the open receiving position. The deep-drawing plate
110 again has, apart from the projections 112 for the deep-drawing,
lowerable stamping elements (not shown) which are responsible for
the corrugating. These stamping elements are so arranged that they
correspond with the centre of the receiving position. The
deep-drawing device 100, i.e. the deep-drawing plate 110 and the
counter-plate 130, are subsequently closed so that the stamping
elements effect preliminary deep-drawing of the deep-draw metal
sheet 10 into the open recesses 103, to approximately 2 mm to 5 mm,
and thus form it to be wavy.
The stamping elements can also be no designed that they merely pass
through the deep-drawing plate 110 and are not connected therewith.
In every case this form of embodiment provides that the lowerable
stamping elements are retracted after the corrugating of the metal
sheet 10, so that only the projections for the consecutively
following deep-drawing still protrude out of the deep-drawing plate
110.
A further drive, by which the metal sheet 10 is deep-drawn, presses
by, for example, a pressure between approximately 200 tonnes and
approximately 700 tonnes, preferably by approximately 300 tonnes. A
first drive, which folds the metal sheet 10, presses together the
tool 106 or the lamellae 101 of the tool 106 by, for example, a
pressure between approximately 0.2 tonnes and approximately 2.5
tonnes, preferably approximately 0.5 tonnes to 1 tonne (1
tonne=1000 kg).
The projections for the deep-drawing preferably have a
cross-sectional profile which tapers or widens towards the surface
of the deep-drawing plate 110. This prevents in certain
circumstances during the deep-drawing process jamming of the metal
sheet 10 in the recesses 103 of the tool 106. This form of mould
also helps, during folding of the corrugated metal sheet 10, to
keep this in position. Moreover, the deep-drawing plate 110 and the
tool 106 are preferably of a hardened material, which is formed by
laser hardening or plasma hardening or induction hardening or
coating hardening, in order to guarantee constantly precise grooves
and webs even after numerous operating processes. In particular,
the edges of the recesses 103 of the tool 106 have to remain hard
and sharp-edged as long as possible in order to guarantee a secure
footing on the webs of the tool.
A variant of embodiment of a deep-drawing device 100 according to
the invention provides projections for the deep-drawing, the
cross-sectional profile of which widens towards the surface of the
deep-drawing plate 110. This thus yields depressions or webs, which
have a trapezium-shaped cross-section, in the workpiece 20 during
the deep-drawing.
A further improved embodiment of a deep-drawing device 100
according to the invention has a positive surface profile at the
underside of the deep-drawing plate 110, thus between the
deep-drawing projections. This profile presses, on attainment of
the maximum stroke of the deep-drawing movement, a number of beads
or notches in the surface of the web for an improved slip
resistance of the tread element webs. If the metal sheet 10 is so
placed in the deep-drawing device 100 that its eventual tread side
lies downwardly, then the bases of the recesses 103 in the tool 106
have to have correspondingly positive surface profiles, for example
dogs. These dogs are preferably arranged at a spacing of about 1 to
3 mm over the depth of the deep-drawing plate underside or over the
depth of the recess bases.
A method according to the invention for deep-drawing with preceding
folding of the metal sheet 10, which is pre-shaped to be wavy, by a
described deep-drawing device 100 provides an additional method
step which facilitates the folding process. In this connection,
after laying of the metal sheet 10 the deep-drawing device 100 is
closed to such an extent that at least one wave elevation of the
metal sheet 10 hits against at least one deep-drawing projection of
the deep-drawing plate 110. It is thereby achieved that the metal
sheet 10 pre-shaped to be wavy is not forced out of the recesses
103 by the closing of the recesses 103 during the folding.
A further method according to the invention for deep-drawing with
preceding folding of the metal sheet 10, which is pre-shaped to be
wavy, by a described deep-drawing device 100 provides an additional
fixing of the workpiece or of the metal sheet 10 by means of the
mentioned harmonica effect or accordion effect or lattice grate
effect. In that case the first three to five lamellae are closed
more quickly and/or more pressurably and thus guarantee gripping or
grabbing or engaging or fixing of the workpiece. The workpiece is,
by this process or method step, prevented or kept or restrained
from jumping out or being forced out or sliding out.
An optional compressed air device, which sucks the metal sheet 10
via holes in the counter-plate or blows the metal sheet 10 via
holes in the deep-drawing plate 110, fulfils the same purpose.
A further optimisation in accordance with the invention of the
folding process can be optionally fulfilled by a flattening plate
which, for example, is introduced simultaneously with the
introduction of the metal sheet 10, which is pre-shaped to be wavy,
between the wave elevations of the metal sheet 10 and the
deep-drawing projections of the deep-drawing plate 110. The
deep-drawing device 100 is subsequently closed again until hitting
of the wave elevations against the underside of the flattening
plate or hitting of the upper side of the flattening plate against
the deep-drawing projections of the deep-drawing plate 110. The
elevations which form during the subsequently following folding
process thus slide along the underside of the flattening plate and
catching of the metal sheet 10 in the deep-drawing device 100 is
thereby prevented.
A further method according to the invention for deep-drawing a
planar (not pre-shaped to be wavy) metal sheet 10 is distinguished
by the following steps. Here use is made of a deep-draw plate 110
having a first arrangement of projections 110 and stamping
elements, which can be lowered into the deep-draw plate 110. In a
first step this first arrangement of the projections 112 and the
stamping elements are lowered into the deep-drawing plate 110. The
planar metal sheet 10 is then introduced between the tool 106 and
the deep-drawing plate 110. The stamping elements are subsequently
so adjusted that the planar metal sheet 10 is shaped to be wavy.
The stamping elements are now lowered and the spacing D between the
tool 106 and the deep-drawing plate 110 is reduced so that the
metal sheet 10 shaped to be wavy bears against an underside 113 of
the deep-drawing plate 110. The metal sheet 10 shaped to be wavy is
further folded by the adjustment of the lamellar gaps 102 of the
tool 106 from the receiving position PA to an end position PE. The
first arrangement of the projections 112 is now adjusted so that
the folded metal sheet 10 is deep-drawn by penetration of the
projections 112 of the deep-drawing plate 110 into the end position
PE of the recesses 103 of the tool 106.
It is possible to realise--by the described deep-drawing device
100, the stated pressing pressures and the described material--for
the production of tread elements or riser elements new, very short
operating cycles which are made up, for example, from the following
individual work cycles: laying in place or clamping in place the
workpiece approximately 0.5 seconds, folding approximately 2
seconds, deep-drawing about 1 second and removal from the mould
(opening, withdrawing workpiece) about 2 seconds.
The deep-drawing device 100 according to the invention and the
method possible therewith are, as already explained in the
introduction, particularly well suited to the production of tread
elements and riser elements of escalator steps. These elements are
made of relatively thin and light metal sheet, which
notwithstanding its property and notwithstanding or as a
consequence of the deep-drawing have to fulfill the prescriptions
and load tests of European Standard EN 115 and American Standard
ASME A17.1-2004. According to these standards the step has to
withstand a static and a dynamic test. In the static test the step
is centrally loaded by a force of 3000 N acting perpendicularly to
the tread element, wherein a deflection of at most 4 mm may arise.
After the action of force, the step may not have any persisting
deformation. In the dynamic test the step is centrally loaded by a
pulsating force, wherein the force varies between 500 and 3000 N at
a frequency of 5 to 20 Hz and lasts for at least 5.times.10.sup.6
cycles. After this test the step may have a residual deformation of
at most 4 mm.
According to the invention, in general flatly shaped materials come
into consideration as the workpiece 10. The term "flatly shaped" is
used to embrace not only pre-corrugated, but also planar metal
sheet. This can be metal sheet 10 in general, be it cooling metal
sheets or sheets for producing heating bodies or facade elements,
solar panels, steel staircases, frame elements or platform
elements.
Coming into consideration as material for a metal sheet which
satisfies these demands are, for example, deep-draw metal sheets of
the steel categories H380, H400, DX 52, DX 56, DX 60, H900 or
H1100. These steel categories are substantially based on the
strength-enhancing effect of microalloying additives such as, for
example, niobium and/or titanium and/or manganese and/or nickel. In
principle, all commercially available deep-draw metal sheets come
into consideration, but also microalloyed steel sheets or metal
sheets which are made of stainless steel, copper, aluminium and
alloys thereof.
The ratio of the metal sheet thickness (0.25 mm to 0.75 mm) to the
deep-drawn height is preferably in the ratio 18 to 39. The sheet
metal thickness, and also the dimensions of the sheet metal panel,
are on the one hand selected so that they fulfill the standard, but
on the other hand so that the deformation through the folding and
deep-drawing directly results in a tread or riser element with the
desired dimensions. In the case of the stated materials this can
be, for example, a sheet metal thickness of less than approximately
0.5 mm, preferably approximately 0.4 mm, and a deep-drawn height
(=web height or groove height) of approximately 10 mm to
approximately 12 mm, preferably approximately 10.25 mm to
approximately 11 mm. The web width lies, for example, between
approximately 2.5 mm and approximately 5 mm, preferably at
approximately 2.6 mm, and the groove width between approximately 5
mm and approximately 7 mm, preferably at approximately 6.4 mm. It
is thus possible to achieve, for example, that, from a sheet metal
panel with a width of approximately 3200 mm, exactly a width of
approximately 1000 mm or approximately 800 mm or approximately 600
mm or approximately 1200 mm or approximately 1400 mm of a tread
element or riser element results after the corrugating and folding
as well as deep-drawing.
Reference is made to the fact that in the foregoing a deep-drawing
device was described in which the plates are arranged horizontally
and also the workpiece comes to lie horizontally on the tool.
However, vertically standing arrangements are also conceivable and
hereby disclosed.
Moreover, reference is made to the fact that it was described in
the foregoing that the tool 106 has (adjustable) recesses 103 and
the deep-drawing plate 110 projections. The converse, namely
projections at the tool 106 and the (adjustable) recesses at the
deep-drawing plate 110, can also be realised, wherein then,
however, a guide for an adjustability of the recesses has to be
provided for the deep-drawing plate 110.
Furthermore, reference is made to the fact that as described in the
foregoing in the case of a deep-drawing device 100 not only the die
plate or the lamellae, but also the ram 120 of the tool 106 or the
deep-drawing plate 110 or even both can fold together the workpiece
10 by a, for example, horizontal auxiliary-drive or drive.
Moreover, the webs preferably have an angle `W` which has an
inclination between 0 degrees and 17 degrees, preferably 2 degrees
to 11 degrees.
The deep-drawing device 100 according to the invention thus makes
possible a method according to the invention in which the workpiece
10 is laid or clamped in position, then folded by closing of the
recesses 103 and only then deep-drawn.
* * * * *